If the receiver does not have some measure of faith, the likelihood of a miracle is next to nothing. God occasionally intervenes despite the unbelief of a receiver rather than in conjunction with his or her faith, but generally, that will not be the case. Today, the receiver is often saddled with the entire burden of failure in the effort to produce the miraculous, but I don't think that represents the total picture of what is going on. Regardless, it cannot be denied that Jesus clearly taught miraculous ministry is received according to one's faith.
The Spirit does as he wills and doesn't do as doesn't will. If the Holy Spirit does not have a mind to do a thing, it just ain't gettin' done! We can exercise some will in relation to the Spirit's will insofar as we go along with what he enables (like in tongues), but his doing is still absolutely necessary to anything miraculous. The only means we have of influencing the impetus of the Spirit is prayer, but the Spirit must be present to do whatever if whatever is to be done.
So, when faith in the doer is contemporaneous with faith in the receiver and the Spirit's willing, a miracle occurs.